Apparatus for printing upon cylindrical objects



Oct. 1-9, 1943.

J. "5. IW EhWIKIN APBARATUS FOR PRINTING CYLINDRIGAL OBJECTS Fil ed Oct. 8. 940

3 Sheets-Sheet 1 m M WM %W A; w

Oct. 19, 1943.' J.-J. MQELWAIN 2,331,991

APPARATUS FOR PRINTING UPON CYLINDRICAL OBJECTS Filed Oct. 8, 1940 SSheets-Sheet z' ,I E: INVENTOR James 1 Mc E/wam WWW/ W Oct. 19; 1943. J. J. M ELWAEN 2,331,991

APPARATUS FOR PRINTING UPON GLINDRICAL OBJECTS Filed Oct. 8, 1940 3 Sheets-Sheet 5 VII IA um VIII/ll 20a /lll/l/l INVENTOR Patented Oct. 19, 1943 APPARATUS FOR PRINTING UPON CYLINDRICAL OBJECTS James J; McElwain, Wheeling, Va.,.. assign r' to. Wheeling Stamping Gompanyt Wh fl ngs.

W. Ya acorporation of West Virginia,

Application October 8, 1940-, Serial N 3 03,

11 Claims.

This invention pertains to the art of printing and is for a machine and. method for printing upon the surface of cylindrical bodies such for example as cylindrical bodies or containers formed from molded plastic. material and such as impact-extruded containers. as, for example, collapsible tubes.

At the present time machines for decorating or printing upon the surface of, hollow cylindrical bodies are provided in which there is a rotatable support or turret which carries a plurality of mandrels projecting. in an axial direction from the turret. These mandrels, while being freely rotatable on the turret, are fixed with reference to the center of the turret. the turret is a printing drum carrying a rubber printing blanket- The blanket. is carried by rotation of the. printing drum past an inking. roll, and then travels, around to engage the. surface of .an article carried on one of the. mandrels, and as the printing blanket rolls. over the article, the article is rotated and ink is transferredto it from the printing blanket. The turret. is. advanced in steps so as to progressively present the several mandrels with the articles thereon to the printing drum. After each article. has been printed upon it is. pulled ofi the. end .of the. mandrel and anotherarticle. is applied in its place. While these machines. are generally satisfactory for printing upon very thin-Walled tubes, such for example as collapsible tubes, considerable difiiculty has been found in adapting them to the printing of molded plastic containers having relatively thicker walls for the reason that the bore of the container is not always concentric with the outer cylindrical surface, or because the Wall of the article is not uniform, or because the exterior surface of the container isto a very-slight extent not a true cylinder. Where any of these conditions exist, the article does not make uniform contact with the printing blanket. Also, the machines. have to be set. up to operate upon one particular diameter of. article with apredetermined Wall thickness. If an. article of a vdifferent diameter is to be .deo rate 0. p nt upon, or if it has a different wall thickness, different mandrels have to be substituted and the machine otherwise changed.

According to the present invention, there is provided. an improvement inmachines, of this general character wherein the mandrels instead of being fixed with respect to the center of the turret on which they are mounted, are mounted in such manner that they may have a limited movement toward or away from the center of Cooperating with.

t e. tu et. an mean i p ovid for r s ent y e ethe mahshols way f m thspsht arran ement. of themandrels enables. the

machine. o automati all c mpensate r such;

varia ionsas. occur imo ded Pla t c. tube o other object to b d co ated! I al enab es apt r to be. u ed whe e Within c ta n aneostm s me man ro maybe em loroo fl or the printing of articles .ofidifterent diameters or f rent well thickne ses Without re ui ng h n e th setup of he mach n wh ou d e ui e am n m m T e inv n ion urthe con m lates co u me the m nd ols n such mann r a to allow the articles to be printed upon to have some slight ni ersal nl meh w th es ec to h his. o the mandrel so thatthe. a he will adjust itself to t s r a oof thoh ih ..e..b. hk t and? th assure more uniform printing; c

e n en on in u e th stop n t me ho of printin of su p rt n the art cle in such a way that it Wi l automatically adjust itself ll .0 1" t c th t ri t n sh lao a d also t o oo whi h nclud s the .ofan adc t h.

T e inventionmay he readily u d rstoo by enc to th aoo hmahriheio fo nss'wh ch i ustrate, one emho m ntiof my in en io a d in which Figure I is a more or less schematic side yi'ew of a printing mac ine e uippe wit hiy.. n o

tion;

Figure II is a side elevation on a larger. scale Portion o thet riet whic carr e th noondrels sho i hefmo htih fo one of the. ma drel's;

Figure III is a top plan view of that portion of e machine wh h isshow in F gure .I

gur is. a s de elevation. of a mold d. via which the present invention is part p llarly adapt,- d to. p nt upon;

Figure V is a side elevationof a po ion of th achine. shown in. Figu e. I. out. On a. large oai w n t h rtsi i th QQSi .oh h t theyo upy at t emome tiwhen theprinting blanket is engagin an articleon one of the mandrel's;

F eu e'V is a trans e fraementairsection in the planeof line VI-VI of Figure Y with he surface. Qfthe p inting. blanket shown in eleya tiQn;

Fi VII s v e e er lly simi ar to ig.-

ure V sh wihsit aohlioation of. m in ent to the Pr n n h n-W l e oll ps e tub by the use of an adapter;

Figure VIII isfa si-de' elevation of one of the adapters Figure IX is a transverse section in the plane of line IX-IX of Figure VIII; and

Figure X is a detailed view showing partly in elevation and partly in section an adapter of different over-all diameter removed from the mandrel.

Referring to the drawings, the printing machine is of a type now generally well known in the art. It is provided with a supporting frame 2 which carries a drum 3 upon a portion of the surface of which is mounted a printing blanket 4. The blanket 4 is usually made of a resilient rubber. A series of rolls transfers ink from a pot 6 to the type carried by a printing roller 5, and roller 5 transfers the ink in the pattern of the type on the surface of the printing blanket t. The rotation of the printing roller and inking rolls is accomplished by the drum 3 which moves the blanket 4 over the surface of the roller 5. Cooperating with the printing drum is an indexing drum or turret I having a mechanism 8 of a type well known to those skilled in the art for rotating the turret 1 in a step-by-step fashion. Machines 'as so constructed are now generally known to the art. Heretofore the turret 'I has been provided with a plurality of mandrels projecting from the end face thereof, these mandrels being fixed but freely rotatable with respect to the aXis of the drum. The indexing mechanism for rotating the turret is arranged so that each mandrel in succession is normally held on a line of centers between the two drums in such position that an article on the surface of the mandrel will be engaged by the blanket 4 as the drum 3 is rotated. The present invention pertains primarily to the construction and arrangement of the mandrels.

According to the present invention the drum or disk I is provided at regularly spaced intervals with transverse pins I!) which pass therethrough. Secured to one end of each pin I0 is an arm II and secured to the other end of each pin is a generally similar'arm I2 which is on the opposite face of the disk I from the arm II. The arms II and I2 are provided with aligned bearings I3 for supporting a spindle I4, the bearings enabling the spindle to rotate freely. I The spindle I4 passes through an elongated opening I5 in the disk 1. Each of the arms II and I2 is provided with a set screw I5 having a disk I 1 thereon that engages a compression spring I8. The opposite end of the spring I8 is supported against an abutment I9 provided on the face of the rotatable head or disk I. The arm IIis fast to the pin I0, and the arm I2 is also fast to the end of the pin I0 so that the assembly comprising the pin I0 and the arms II and I2 is a unit carrier for supporting the spindle I4. The spring I8 tends to yieldably urge the spindle outwardly away from the center of the disk I, and the slot I5 through which this spindle passes limits the range of movement of the spindle toward and away from the center.

Projecting from one end of the spindle I4 is a mandrel Ma. This mandrel is preferably made larger at the center than at its ends, preferably being slightly convexed.

In the operation of the machine for the decoration of molded cylindrical objects such for example as the vials A shown in Figures IV and VI, which for example may be of plastic material or glass, the vials are slipped onto the mandrels in a position remote from the printing position. As the disk I rotates, the vials are advanced progressively to the printing position.

The 75 springs I8 normally notwithstanding that there may be certain irregularities in the vial due to the inside not being concentric with the outside or due to inequalities of the wall thickness or due to the article not being truly cylindrical. Moreover, because of the contour of the mandrels, the cylindrical articles adjust themselves on the mandrels so as to press uniformly against the printing blankets. The resilient mounting of the mandrel in combination with the universal movement which the article has on the mandrel by reason of the convex contour of the mandrel thus enables the article to be evenly and uniformly decorated or printed upon.

The same machine may be used for printing upon easily deformable thin-walled receptacles such for example as collapsible tubes. Where the machine is to be used for printing upon collapsible tubes, the end of the mandrel Ma is preferably provided with a projecting stud 20 which is necked-in. Slipped over the mandrel is an adapter 2i in the form of a sleeve having rigid walls. The outer end of the sleeve is closed by a plug 25a, and on the inner end of this plug is a clip 22. This clip snaps over the necked stud 2D and thus holds the adapter against 1ongitudinal movement on the mandrel. At the same time the clip is suificiently resilient and engages the stud loosely enough so that the adapter can adjust itself on the convexed mandrel. The adapter is necessary in order to support the tube and prevent it from being deformed during the operation of printing. The adapter of course is generally similar in its contour to the vial A described in connection with Figures I to V1 inclusive. The tube, designated B in Figure VII, closely fits over the adapter so that for all practical purposes the tube and the adapter together become a single unit on the mandrel.

Where a tube of larger diameter is to be printed upon, the adapter 2I as shown in Figure X, has a thicker wall but has the same internal diameter. The wall thickness is such that the adapter will fit snugly into the tube. Because of the fact that the mandrel which carries the adapter may move under pressure toward the center of the drum or turret on which it is carried, the adapter of larger diameter may be used without changing the printing machine except insofar as a larger diameter tube may require some change in the printing blanket.

The resilient support of the mandrels also enables thicker and more elastic printing or transfer blankets to be used on the printing drum, and this is desirable because it permits of greater tolerances in the machine without sacrifice o1- results.

While I have illustrated and described in detail one preferred embodiment of my invention, it will be understood that this is merely by way of illustration and that various changes and modifications may be made in the construction of the machine within the contemplation of my invention and within the scope of the following claims.

I claim as my invention: 1. Printing apparatus of the class described comprising a rotatable head, a carrier on the head movable toward and away from the center thereof, a rotatable mandrel on the carrier, and means for yieldably urging the carrier in a direction away from the center of the head, said mandrel having a container-supporting surface thereon of larger diameter at the center than at its ends.

2. Printing apparatus of the class described comprising a rotatable head, a pair of arms, one at each side of the head, a pin fastened through the head on which the arms are mounted, a spindle rotatably mounted in the two arms and projecting in an axial direction from the end of the head, the head being slotted in a generally radial direction to enable the arms with the mandrel supported thereby to move arcuately to a limited extent toward and away from the center of the head, means for resiliently pressing the arms outwardly toward the periphery of the head, and a printing drum cooperatingwith the mandrel.

3. Printing apparatus of the class described comprising a turret having a plurality of mandrels projecting in an axial direction therefrom and having a printing drum cooperating with the mandrels characterized by the provision of means for yieldably supporting the mandrels for movement in a direction toward and away from the center of the turret, and an adapter slidably carried on the mandrel for ready removal said adapter having a substantially cylindrical bore and said mandrel having an adapter holding portion which is convex, and resilient interengaging means between said mandrel and said adapter.

4. Printing apparatus of the class described comprising a turret having a plurality of mandrels projecting in an axial direction therefrom and having a printing drum cooperating with the mandrels, means for yieldably supporting the mandrels for movement in a direction toward and away from the center of the turret, and an adapter removably carried on the mandrel said adapter having a substantially cylindrical bore and said mandrel having an adapter holding portion which is convex, and resilient interengaging means between said mandrel and said adapter, whereby, the adapter is supported on the mandrel in such manner that it may wobble to a limited extent.

5. For use in a printing machine of the class described wherein there is a rotatable head hav-- ing a plurality of axially projecting mandrels arranged about the center, a carrier mounted on the head movable toward and away from the center, a mandrel rotatably supported in said car rier, and means for resiliently urging the carrier outwardly away from the center of the drum, said mandrel having a work-holding portion which is convexed.

6. For use in a printing machine of the class described wherein there is a rotatable head having a plurality of axially projecting mandrels arranged about the center, a carrier mounted on the head movable toward and away from the center, a mandrel rotatably supported in said carrier, means for resiliently urging the carrier outwardly away from the center of the drum, said mandrel having a work-holding portion which is convexed, a rigid adapter on the Work-holding portion of the mandrel having a cylindrical internal bore substantially equal to the maximum diameter of the work-holding portion of the mandrel, and means for releasably holding the adapter on the end of the mandrel.

7. For use in a printing machine of the class described wherein there is a rotatable head having a plurality of axially projecting mandrels arranged about the center, a carrier mounted on the head movable toward and away from the center, a mandrel rotatably supported in said carrier, means for resiliently urging the carrier outwardly away from the center of the drum, said mandrel having a work-holding portion which is convexed, a rigid adapter on the workholding portion Of the mandrel having a cylindrical internal bore substantially equal to the maximum diameter of the work-holding portion of the mandrel, and means for releasably holding the adapter on the end of the mandrel, said means comprising a resilient clip on the inner end of said adapter, the mandrel having a necklike stud at the end thereof for cooperation withthe clip.

8. A unit for attachment to turret type printing machines for adapting such machines to the printing of cylindrical objects, such as soft collapsible tubes, comprising a mandrel having a convexed working portion, a carrier providing a bearing for one end of the mandrel, means for pivotally supporting the carrier on a turret, means for yieldably urging the carrier outwardly away from the axis of the carrier, a rigid cylindrical adapter fitted over the working portion of the mandrel having a cylindrical interior substantially equal in diameter to the maximum diameter of the convexed portion of the mandrel and having a cylindrical exterior of a diameter to have a sliding fit in the article to be printed upon, and means for releasably holding the adapter against endwise movement on the mandrel but permitting the same to wobble on the convexed portion of the mandrel.

9. Printing apparatus of the class described comprising a rotatable head, a pivoted carrier on the head movable in an arc toward and away from the center thereof, a rotatable mandrel on the carrier, and means for yieldably urging the carrier in a direction away from the center of the head, the pivot about which the arcuate movement of the carrier takes place being to one side of a radius extending from the center of the head to the center of the mandrel, and means for limiting the movement of the carrier, whereby the center of the mandrel may never be in line with a radius extending from the center of the head to the center about which the carrier pivots, the pivot of said carrier being located in advance of said mandrel with respect to the direction of movement of said head, said pivot being radially nearer the center of said head than said mandrel when said mandrel is moved away from the center of said head.

10. For use in printing apparatus having a printing drum and a rotatable head, a carrier pivotally supported on the head movable in an are about its pivot point toward and away from the periphery thereof, bearings in the carrier eccentric to the pivot point thereof and a mandrel rotatably supported in the bearings, means for yieldably urging the carrier in a direction away from the center of the head, and means whereby the arcuate movement of the carrier is limited to a range where a radius from the center of the head to the center of the mandrel is always angularly displaced to a radius from the center of the head to the center of the pivot, the pivot of said carrier being located in advance of said mandrel with respect to the direction of movement of said head, said pivot being radially nearer the center of said head than said mandrel when said mandrel is moved away from the center of said head.

11. Printing apparatus of the class described comprising a printing drum, a rotatable head cooperating with the drum having a plurality of carriers thereon, a mandrel mounted in each carrier, each carrier with its mandrel being pivotally supported to permit a limited movement of the mandrel in an arc toward and away from the center of the drum, resilient; means for urging the carrier and the mandrel in a direction away from the center of the drum, and means for limiting the arc of movement of the carriers and mandrels, to an extent such that the pivot point of each carrier is always circumferentially offset from a radius extending from the center of the head to the center of the mandrel 0n the carrier, the pivot of said carrier being located in advance of said mandrel with respect to the direction of movement of said head, said pivot being radially nearer the center of said head than said mandrel when said mandrel is moved away from the center of said head.

JAMES L. MCELVJAIN. 

